The present invention is directed to a blended yarn, and more particularly to an olefin blended yarn to obtain a high bulk and at the same time provide a light weight yarn.
Olefin is a group of unsaturated hydrocarbons of the general formula C.sub.x H.sub.2n, being a manufactured fiber in which the fiber-forming substance is any long chain synthetic polyner composed of at least 85% by weight of ethylene, propylene, or other olefin units.
Olefin is well known in the textile art, but has had limited use because of its low melting point and its inability to retain a constant dye color over a period of time when piece dyed. Accordingly, the olefin is usually dyed during the formation of the filament.
U.S. Pat. No. 3,295,308 discloses the manufacture of multifilament polyolefin carpets madeup of filaments, particularly polypropylene multifilaments, having a predetermined cross-section wherein the yarn in the carpet has sufficient flexibility for good processing and yet also has increased cover, bulk and stiffness and other improved properties.
In the textile art, it is desired in many cases to produce yarn which possesses a high bulk. U.S. Pat. No. 3,587,220 teaches that the finishing treatments of yarns or fabrics may be used to bring about the shrinkage of the shrinkable fiber components therein for the development of bulk. This patent relates to woven or knitted fabrics which include melt colored polyester staple fibers and polyester staple fibers of high shrinkage in their construction. Particularly, the woven or knitted fabrics comprise 65-90% by weight of polyester staple fibers of which 15-40% expressed on weight of the fabric are fibers having a shrinkage of at least 25%, and 75-25% by weight are polyester fibers of normal shrinkage, at least some of either kind of polyester fibers being melt colored polyester fibers, and 35-10% expressed on the weight of the fabric of wool or cellulosic fibers. Shrinkage of the colored fibers cause a lightening of the fabric color because of the concentration of these fibers within the yarn. The polyester fiber can be a polyethylene terephthalate.
Normally, if a high bulk yarn is desired, the twist would be lowered, however, the strength would be sacrificed. U.S. Pat. No. 3,371,475 discloses a spun yarn having a low twist multiplier including blends of polyethylene terephthalate with minor portions of rayon and with minor portions of cotton so that the yarn possesses a high bulk and covering power with a good degree of strength. Particularly, the measured stapled length is from 2.25 to 3.0 inches and the fiber denier is less than 2.0, so that the normal yarn twist multiplier of 3.5 to 4.0 can be drastically reduced to a value below 2.0 to produce bulky polyethylene terephthalate yarn which maintains a surprisingly degree of strength, the twist multiplier preferably being from 1.65 to 1.85.
Naturally occuring fibers, such as cotton fibers have been treated with various antimicrobial agents to inhibit the growth of bacteria and fungus. U.S. Pat. No. 3,959,556 discloses antimocrobial blended yarns and fabrics comprised of naturally occuring fibers wherein the antimicrobial properties are imparted to the naturally occuring fibers by intimately admixing the naturally occuring fibers with synthetic fibers. The synthetic fibers, which include polyolefins, particularly polypropylene and polyethylene, contain at least 0.1% by weight of the antimicrobial agent wherein the resultant filaments are chopped into short fiber lengths and blended with naturally occuring fibers, such as cotton and flax or wool, at any stage of the yarn forming process according to known techniques. This yarn may be used in the formation of fabrics and garments by weaving, knitting or the like.
U.S. Pat. No. 3,524,542 discloses a heat sealable bonding cord which will retain substantial amounts of elongation resistance during heat sealing operations in the wrapping of packages. The bonding cord is composed of blends of thermoplastic and non-thermoplastic material wherein the thermoplastic materials include polypropylene and polyester, and the non-thermoplastic materials include cotton, rayon, siliceous fibers or wool.
U.S. Pat. No. 3,007,227 discloses a stretchable fabric having elastic properties without resorting to the use of any natural rubber in the fabric. The stretchable fabric is a blend of intermingled fibers including a hard inelastic staple fiber and an elastomeric staple fiber, and is formed by the spinning of these blends into a textile material. The hard inelastic staple fiber may be prepared from any synthetic fiber-forming materials or from any natural fiber, such ascotton, wool, silk, jute, linen or a blend of two or more hard fibers.
Even though the above patents disclose the use of polyolefin, the production of yarn which possesses a high bulk, and blends all naturally occuring fibers such as cotton with synthetic fibers, none of the above patents teach or disclose a blend of olefin with a naturally occuring fiber such as cotton which becomes a high bulk yarn under controlled high heat levels.